From 6edb8cd87cca5dd4389d4ea2d84b66ea94341bbd Mon Sep 17 00:00:00 2001 From: Kerem Karabay Date: Fri, 5 Jul 2024 11:17:42 +0000 Subject: [PATCH] HID: core: add helper for finding a field with a certain usage This helper will allow HID drivers to easily determine if they should bind to a hid_device by checking for the prescence of a certain field when its ID is not enough, which can be the case on USB devices with multiple interfaces and/or configurations. Convert google-hammer driver to use it, and remove now superfluous hammer_has_usage(). [jkosina@suse.com: expand changelog with the information about google-hammer being added as user of this API ] Signed-off-by: Kerem Karabay Signed-off-by: Aditya Garg Signed-off-by: Jiri Kosina --- drivers/hid/hid-core.c | 25 +++++++++++++++++++++++++ drivers/hid/hid-google-hammer.c | 27 ++------------------------- include/linux/hid.h | 2 ++ 3 files changed, 29 insertions(+), 25 deletions(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 988d0acbdf04..caeba5487b69 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1912,6 +1912,31 @@ int hid_set_field(struct hid_field *field, unsigned offset, __s32 value) } EXPORT_SYMBOL_GPL(hid_set_field); +struct hid_field *hid_find_field(struct hid_device *hdev, unsigned int report_type, + unsigned int application, unsigned int usage) +{ + struct list_head *report_list = &hdev->report_enum[report_type].report_list; + struct hid_report *report; + int i, j; + + list_for_each_entry(report, report_list, list) { + if (report->application != application) + continue; + + for (i = 0; i < report->maxfield; i++) { + struct hid_field *field = report->field[i]; + + for (j = 0; j < field->maxusage; j++) { + if (field->usage[j].hid == usage) + return field; + } + } + } + + return NULL; +} +EXPORT_SYMBOL_GPL(hid_find_field); + static struct hid_report *hid_get_report(struct hid_report_enum *report_enum, const u8 *data) { diff --git a/drivers/hid/hid-google-hammer.c b/drivers/hid/hid-google-hammer.c index 6e4ebc349e45..4e79fafeeafa 100644 --- a/drivers/hid/hid-google-hammer.c +++ b/drivers/hid/hid-google-hammer.c @@ -418,38 +418,15 @@ static int hammer_event(struct hid_device *hid, struct hid_field *field, return 0; } -static bool hammer_has_usage(struct hid_device *hdev, unsigned int report_type, - unsigned application, unsigned usage) -{ - struct hid_report_enum *re = &hdev->report_enum[report_type]; - struct hid_report *report; - int i, j; - - list_for_each_entry(report, &re->report_list, list) { - if (report->application != application) - continue; - - for (i = 0; i < report->maxfield; i++) { - struct hid_field *field = report->field[i]; - - for (j = 0; j < field->maxusage; j++) - if (field->usage[j].hid == usage) - return true; - } - } - - return false; -} - static bool hammer_has_folded_event(struct hid_device *hdev) { - return hammer_has_usage(hdev, HID_INPUT_REPORT, + return !!hid_find_field(hdev, HID_INPUT_REPORT, HID_GD_KEYBOARD, HID_USAGE_KBD_FOLDED); } static bool hammer_has_backlight_control(struct hid_device *hdev) { - return hammer_has_usage(hdev, HID_OUTPUT_REPORT, + return !!hid_find_field(hdev, HID_OUTPUT_REPORT, HID_GD_KEYBOARD, HID_AD_BRIGHTNESS); } diff --git a/include/linux/hid.h b/include/linux/hid.h index 1533c9dcd3a6..2deff79f39a1 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -940,6 +940,8 @@ extern void hidinput_report_event(struct hid_device *hid, struct hid_report *rep extern int hidinput_connect(struct hid_device *hid, unsigned int force); extern void hidinput_disconnect(struct hid_device *); +struct hid_field *hid_find_field(struct hid_device *hdev, unsigned int report_type, + unsigned int application, unsigned int usage); int hid_set_field(struct hid_field *, unsigned, __s32); int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size, int interrupt);